[ale] comcast business + mail server = static ip?

[Lightner, Jeff]

I haven't used Comcast for this but do know that at least once site (Paypal as I recall) rejected OUR email here because they thought we had a "generic" reverse for our MX record's IP.  (We do under THEIR definition but I didn't really give a damn and asked how the request to make a DNS change for that was business related which made the question go away.)

I suspect however that many more vendors are concerned about "generic" IPs from known "home" ISP providers like Comcast/AT&T than there are for "generics" provided by delegated DNS servers.





-----Original Message-----
From: ale-bounces at ale.org [mailto:ale-bounces at ale.org] On Behalf Of mike at trausch.us
Sent: Wednesday, August 01, 2012 2:27 PM
To: ale at ale.org
Subject: Re: [ale] comcast business + mail server = static ip?

On 08/01/2012 12:27 PM, Scott Plante wrote:
> I seem to recall a lot of mail servers will block your mail as spam if
> the dns record is <86400 (24hr). Also there are lists of dynamic
> ranges that your address may be in and cause your mail to be blocked.
> Not having a reverse DNS entry will also cause some of your email to
> be blocked as spam. This is all for outgoing mail, so you may be able
> to get around it by routing all your outgoing mail through the Comcast
> SMTP server, but you probably want to get the static IP or use a mail host.

I haven't had mail rejected based on the DNS TTL (for my domain, the TTL has been 3600 almost forever).

But I have had:

  * Mail from static IP addresses formerly owned by bad netizens blocked
    (not marked spam, but completely rejected) due to rules in a DNS
    blacklist

  * Mail from addresses explicitly marked dynamic either blocked or put
    in spam folders at the destination.

  * Mail from SMTP servers without a valid RDNS PTR either blocked or
    put in spam folders at the destination.

One setup I manage has mail coming directly to the mail server, but all outbound mail goes through a satellite on Linode's network.  That's worked well for me for the past few years.

        --- Mike

--
A man who reasons deliberately, manages it better after studying Logic than he could before, if he is sincere about it and has common sense.
                                   --- Carveth Read, “Logic”





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